September 10, 2010

Genetic differences between five European populations (Moskvina et al. 2010)

Notice (on the left) the number of SNPs with significant (p=0.05) differences between population varies between a low for the Scotland-Ireland pair to a high for the Sweden-Portugal one.


The supplementary material is also interesting. In Supp. Fig. 2 you can see the occurrence of 4 distinct clusters corresponding to the four corners of Europe, and also a barely perceptible tilting of Scotland toward Sweden relative to Ireland, within the NW cluster. As always, we should not interpret this as a lack of distinctiveness of the two populations, as such distinctiveness may hide in either higher-order dimensions, or a combination of more markers/individuals to be able to discern it. We could, however, say, as common sense would also dictate that these two populations are very close to each other in the European context.

Human Heredity Vol. 70, No. 2, 2010

Genetic Differences between Five European Populations

Valentina Moskvina et al.

Abstract

Aims: We sought to examine the magnitude of the differences in SNP allele frequencies between five European populations (Scotland, Ireland, Sweden, Bulgaria and Portugal) and to identify the loci with the greatest differences. Methods: We performed a population-based genome-wide association analysis with Affymetrix 6.0 and 5.0 arrays. We used a 4 degrees of freedom χ2 test to determine the magnitude of stratification for each SNP. We then examined the genes within the most stratified regions, using a highly conservative cutoff of p less than 10–45. Results: We found 40,593 SNPs which are genome-wide significantly (p ≤ 10–8) stratified between these populations. The largest differences clustered in gene ontology categories for immunity and pigmentation. Some of the top loci span genes that have already been reported as highly stratified: genes for hair color and pigmentation (HERC2, EXOC2, IRF4), the LCT gene, genes involved in NAD metabolism, and in immunity (HLA and the Toll-like receptor genes TLR10, TLR1, TLR6). However, several genes have not previously been reported as stratified within European populations, indicating that they might also have provided selective advantages: several zinc finger genes, two genes involved in glutathione synthesis or function, and most intriguingly, FOXP2, implicated in speech development. Conclusion: Our analysis demonstrates that many SNPs show genome-wide significant differences within European populations and the magnitude of the differences correlate with the geographical distance. At least some of these differences are due to the selective advantage of polymorphisms within these loci.

Link

12 comments:

axxuary said...

This reminds me of something. How do the nations line up on your EuroDNACalc? I would think Ireland is the pole for NW; Greece for SE. Is that so?

Average Joe said...

I would think Ireland is the pole for NW

Wouldn't Finland be the pole for NW?

Annie Mouse said...

As suspected.

Scotland and Ireland very substantially overlap (like England and Ireland). Scotland looks to be almost indistinguishable for England (Orkney tilt). I imagine most of the Irish difference is in Galway/west coast.

What I am seeing so far collectively from the literature is essentially one people populating the two islands with a southern coastal influence on the west coast of Ireland

Maybe more info will emerge with the fine details/haplogroups.

Average Joe said...

The fact that the Scottish cluster is between Ireland and Sweden seems to support the position that Britain is most Celtic in the west and most Germanic in the east. It is a pity that the English were not included in the analysis.

Annie Mouse said...
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Annie Mouse said...
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Annie Mouse said...

England has been done in other studies. It looks exactly like the Scottish spread.

roni_buckley said...

Hi there this is nothing to do with the analysis of European peoples, but I am interested to know if anyone has done a study on the similarities between the Dravidian tribes of south India for eg the Budigas (not sure how to spell it in English) or even Tamil, Telegu, Malyalam etc peoples and Aborigne tribes. When I lived in these parts the first thing that struck me about the Budigas was how they looked identical to Aborigne people. The similarity was amazing. I have just by chance listened to some Aborigne tribes taking and am struck between the similarity in the language. Can anyone help? Thanks

pduffy81 said...
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pduffy81 said...

Of course if you believe the bbc potentially up to 1/4 of the population of Great Britian has some irish ancestory.
http://news.bbc.co.uk/2/hi/uk_news/1224611.stm

10% have at least one Irish grandparent and can thus claim Irish citizenship. Given that there were laws been passed to deal with migrant irishmen back in Elizabethean times I wouldn't be surprised if this has had a knock-on effect in Genetic makeup of island of Britian.

Annie Mouse said...

Look at the red Irish. It lies under the green Scottish/English mirroring it. That is not Irish immigrants.

Henrik said...

Why do the blue "Swedish" dots cover big parts of Finland and also a small part of Norway? They, especially when it comes to the Finns, differ from each other, and can certainly not be labeled under the same name.